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Zinc plated and clear chromate rinse

We make custom metal parts. My American customer wants "Zinc plated and clear chromate rinse" on HR P&O steel. But my supplier said I cannot have Zinc plating and Then Chrome plating. He said I have to do Nickel plating first and then chrome plating. I don't understand what is "Zinc plated and clear chromate rinse". Please help to explain and advise if my supplier is correct.

Thank you,

Roger Chiang
- Taipei, Taiwan
2003

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First of two simultaneous responses --

Your customer should give you a clear, detailed, spec with an ASTM, Mil, ISO, or other spec number clearly describing what he wants because confusion like this should not be happening.

Zinc plated components which lack a post-treatment will quickly form white rust, so virtually all zinc plated parts receive a "chromate" post-treatment. It has nothing to do with chrome plating, but does have to do with a chrome-bearing treatment. "Clear" chromate means that the post-treatment delivers a bright, clear or bluish tint to the zinc plating as opposed to the equally common "yellow" chromate.

So loose a "specification" always holds the potential for lose-lose arguments for both parties, but in these days when many applications require hexavalent-chromium-free topcoats, it is a recipe for financial disaster.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

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Second of two simultaneous responses --

If I had a vendor that did not know the difference between a chromate conversion coating and chrome plating, I would find another vendor immediately. Send your current vendor a copy of this and give him a week to clean up his act.

James Watts
- Navarre, Florida
2003

Thank you very much. I learn some thing from both of you gentlemen. However, part of the misunderstanding comes from direct translation from English to Chinese and local description of the plating. Next time, when you deal with a stamping factory in China, please make sure your idea understood well.

Roger Chiang
- Taipei, Taiwan
2003

Communication is a common problem, even when translations are not involved. Our answers were by what you comunicated to us and how what we thought you meant.

James Watts
- Navarre, Florida
2003